Question: $J$ $K$ $L$ If: $ JL = 89$, $ KL = 3x + 9$, and $ JK = 9x + 8$, Find $KL$.
Solution: From the diagram, we can see that the total length of ${JL}$ is the sum of ${JK}$ and ${KL}$ $ {JK} + {KL} = {JL}$ Substitute in the expressions that were given for each length: $ {9x + 8} + {3x + 9} = {89}$ Combine like terms: $ 12x + 17 = {89}$ Subtract $17$ from both sides: $ 12x = 72$ Divide both sides by $12$ to find $x$ $ x = 6$ Substitute $6$ for $x$ in the expression that was given for $KL$ $ KL = 3({6}) + 9$ Simplify: $ {KL = 18 + 9}$ Simplify to find ${KL}$ : $ {KL = 27}$